Kansas shale clay from the Pennsylvanian period - about 300 million years ago provided a metallic sheen over which kaolin and feldspar engode was added with a house painting brush for a hakeme effect. The glaze is colored with iron and copper, fluxed with barium and boron. The gloss surface of this glaze is basically the same whether fired to cone 2 or 10. Wood-fired and reduction gas fired.
